Mariah Carey should really stop pretending she doesn't know who Jennifer Lopez is

The Hero singer has insisted that she remains unaware of the Maid in Manhattan actress and fellow pop diva's existence, as she repeated the same phrase she had previously used to discard the Waiting for Tonight hitmaker 10 years ago.

Asked by TMZ about her previous dismissal of her chart rival, Mariah said: "I still don't know her."

Watch the video clip here:

Meanwhile, Jennifer spoke last week about the 45-year-old star's previous comments, attributing it to "forgetfulness".

She said: "Mariah is forgetful I guess! We've met many times."

Despite Mariah's denials, Jennifer caused a stir when it emerged she had attended almost every performer's Las Vegas residency - except Mariah's.

But the American Idol judge - who has her own residency in the city - insisted it wasn't a deliberate snub.

She said: "I think last year when Mariah's residency started I was already here in New York filming Shades of Blue and doing Idols on the weekends- didn't have a lot of time.

"Then I started preparing my own. I don't think there's been a time when I could have seen it."